Merge pull request #17874 from mheon/sqlite_fixes

Sqlite fixes

libpod/sqlite_state.go

@@ -29,6 +29,30 @@ type SQLiteState struct {
 	runtime *Runtime
 }
 
+const (
+	// Deal with timezone automatically.
+	sqliteOptionLocation = "_loc=auto"
+	// Set the journal mode (https://www.sqlite.org/pragma.html#pragma_journal_mode).
+	sqliteOptionJournal = "&_journal=WAL"
+	// Force WAL mode to fsync after each transaction (https://www.sqlite.org/pragma.html#pragma_synchronous).
+	sqliteOptionSynchronous = "&_sync=FULL"
+	// Allow foreign keys (https://www.sqlite.org/pragma.html#pragma_foreign_keys).
+	sqliteOptionForeignKeys = "&_foreign_keys=1"
+	// Enable cache sharing for threads within a process
+	sqliteOptionSharedCache = "&cache=shared"
+	// Make sure that transactions happen exclusively.
+	sqliteOptionTXLock = "&_txlock=exclusive"
+
+	// Assembled sqlite options used when opening the database.
+	sqliteOptions = "db.sql?" +
+		sqliteOptionLocation +
+		sqliteOptionJournal +
+		sqliteOptionSynchronous +
+		sqliteOptionForeignKeys +
+		sqliteOptionSharedCache +
+		sqliteOptionTXLock
+)
+
 // NewSqliteState creates a new SQLite-backed state database.
 func NewSqliteState(runtime *Runtime) (_ State, defErr error) {
 	state := new(SQLiteState)
@@ -45,7 +69,7 @@ func NewSqliteState(runtime *Runtime) (_ State, defErr error) {
 		return nil, fmt.Errorf("creating root directory: %w", err)
 	}
 
-	conn, err := sql.Open("sqlite3", filepath.Join(basePath, "db.sql?_loc=auto"))
+	conn, err := sql.Open("sqlite3", filepath.Join(basePath, sqliteOptions))
 	if err != nil {
 		return nil, fmt.Errorf("initializing sqlite database: %w", err)
 	}
@@ -63,18 +87,9 @@ func NewSqliteState(runtime *Runtime) (_ State, defErr error) {
 		return nil, fmt.Errorf("cannot connect to database: %w", err)
 	}
 
-	// Enable foreign keys constraints, which we use extensively in our
-	// tables.
-	if _, err := state.conn.Exec("PRAGMA foreign_keys = ON;"); err != nil {
-		return nil, fmt.Errorf("enabling foreign key support in database: %w", err)
-	}
-	// Enable WAL mode for performance - https://www.sqlite.org/wal.html
-	if _, err := state.conn.Exec("PRAGMA journal_mode = WAL;"); err != nil {
-		return nil, fmt.Errorf("switching journal to WAL mode: %w", err)
-	}
-	// Force WAL mode to fsync after every transaction, for reboot safety.
-	if _, err := state.conn.Exec("PRAGMA synchronous = FULL;"); err != nil {
-		return nil, fmt.Errorf("setting full fsync mode in db: %w", err)
+	// Migrate schema (if necessary)
+	if err := state.migrateSchemaIfNecessary(); err != nil {
+		return nil, err
 	}
 
 	// Set up tables
@@ -82,10 +97,6 @@ func NewSqliteState(runtime *Runtime) (_ State, defErr error) {
 		return nil, fmt.Errorf("creating tables: %w", err)
 	}
 
-	if err := state.migrateSchemaIfNecessary(); err != nil {
-		return nil, err
-	}
-
 	state.valid = true
 	state.runtime = runtime
 

libpod/sqlite_state_internal.go

@@ -16,6 +16,20 @@ import (
 )
 
 func (s *SQLiteState) migrateSchemaIfNecessary() (defErr error) {
+	// First, check if the DBConfig table exists
+	checkRow := s.conn.QueryRow("SELECT 1 FROM sqlite_master WHERE type='table' AND name='DBConfig';")
+	var check int
+	if err := checkRow.Scan(&check); err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil
+		}
+		return fmt.Errorf("checking if DB config table exists: %w", err)
+	}
+	if check != 1 {
+		// Table does not exist, fresh database, no need to migrate.
+		return nil
+	}
+
 	row := s.conn.QueryRow("SELECT SchemaVersion FROM DBConfig;")
 	var schemaVer int
 	if err := row.Scan(&schemaVer); err != nil {
@@ -24,6 +38,7 @@ func (s *SQLiteState) migrateSchemaIfNecessary() (defErr error) {
 			// Schema was just created, so it has to be the latest.
 			return nil
 		}
+		return fmt.Errorf("scanning schema version from DB config: %w", err)
 	}
 
 	// If the schema version 0 or less, it's invalid